/*
 * $URL: http://ripple.googlecode.com/svn/trunk/ripple-core/src/main/java/net/fortytwo/ripple/query/StackEvaluator.java $
 * $Revision: 218 $
 * $Author: parcour $
 *
 * Copyright (C) 2007-2011 Joshua Shinavier
 */


package net.fortytwo.ripple.query;

import net.fortytwo.ripple.model.StackContext;
import net.fortytwo.ripple.model.StackMapping;
import net.fortytwo.ripple.model.NullStackMapping;
import net.fortytwo.ripple.RippleException;

/**
 * Author: josh
 * Date: Feb 11, 2008
 * Time: 3:15:35 PM
 */
public abstract class StackEvaluator extends Evaluator<StackContext, StackContext, RippleException> implements StackMapping
{
	public int arity()
	{
		return 1;
	}

    // TODO
    public StackMapping getInverse() throws RippleException
    {
        return new NullStackMapping();
    }
}
